This invention relates generally to plumbing traps, and has particular reference to a novel clean out arrangement for a sink trap.
Plumbing traps having access openings for clean out purposes have been known for many years. In most instances, the access openings are relatively small and are threaded to receive an externally threaded plug that normally closes the opening. This construction has the disadvantage that a wrench is required to remove the plug and the homeowner may not have a wrench of the proper type. Also, if after removing the plug a plumber's snake is passed through the opening to clear out a clogged portion of trap, the snake will after a relatively few applications severely damage the threads in the opening requiring the installation of a new trap.
Another disadvantage of the trap access openings of the prior art is that they are frequently located at the lowest point on the trap. This means that there may be considerable spillage when the plug is removed, and just before removal liquid in the trap may spurt out in many different directions. U.S. Pat. No. 598,992 granted Feb. 15, 1898 to Hosford and U.S. Pat. No. 3,470,900 granted Oct. 7, 1969 to Rothauser disclose threaded access openings located at or close to the lowest point on the trap. U.S. Pat. No. 3,168,104 granted Feb. 2, 1965 to Mathis discloses a threaded access opening located at an upper bend of a trap. These three patents are the closest prior art known to the applicant.